Whichever Republican candidate comes out on top in Arkansas is likely to carry the state in November's general election, too - it's a solid-red state with little love for President Obama. There are whispers that a write-in Democratic candidate could put up a fight against the president in the state, although that would have no real political significance.
Both states will also feature primaries for races in the House of Representatives, which should prove more interesting to watch than the pretty-much-settled national-level showdown.
In all of Tuesday night's contests, politicians will be using social media to garner support, voters will be talking about their candidate of choice and journalists will be covering the election night story. Follow Mashable to see the best examples of social media's use throughout the night.
[View the story "The Kentucky and Arkansas Primaries on Social Media" on Storify]